1. Costa, E.T., Leeman, S., Richardson, P.A.C., and Seggie, D.A., 1986, Measurement and calibration of transducer fields, in: “Proceed ings of The Institute of Acoustics”, vol. 8, part 2, R. Lawrence (ed.), The Institute of Acoustics, Edimburgh.
2. Costa, E.T., Leeman, S., and Hoddinott, J.C., 1987, Overcoming the ultrasound diffraction artefact. II. Attenuation estimation, characteristic impedance and nonlinear propagation, Revista Brasileira de Engenharia, Caderno de Engenharia Biomedica, 4(1):47.
3. Freedman, A., 1961, PhD Thesis (University of London), released as an Establishment Report entitled ‘The formation of acoustic echoes in fluids’ by the Admiralty Underwater Weapons Establishment in 1962, Portland, UK.
4. Gore, J.C., and Leeman, S., 1977, Echo structure in medical ultrasound pulse-echo scanning, Phys. Med. Biol., 22(3):431.
5. Hutchins, L. and Leeman, S., 1981, Tissue parameter measurement and imaging, in: “Acoustical Imaging 11”, J.P. Powers (ed), Plenun, New York.